Hello Dear,

For person with disability, there is a 3% reservation quota in every examination and job vacancy. To be considered under Visually impaired PWD category one must complete absence of sights or low vision.The lens power of 8 diopters is not the parameter to qualify you for benefits available under PWD. It is visual acuity that decides how much percentage of visual disability you have.  I am sure having lens power of 8 diopters means very high hypermetropia category but you have to get yourself checked and assessed by a civil surgeon at district level government hospital that is authorized to issue a Disability Certificate.

Good Luck